The event is best known for considerable violence, including the stabbing death of Meredith Hunter and three accidental deaths: two caused by a hit-and-run car accident, and one by LSD-induced drowning in an irrigation canal.[4] Scores were injured, numerous cars were stolen and then abandoned, and there was extensive property damage.[5][6]

The concert featured (in order of appearance): Santana, The Jefferson Airplane, The Flying Burrito Brothers and Crosby, Stills, Nash & Young, with the Rolling Stones taking the stage as the final act.[7] The Grateful Dead were also scheduled to perform following CSNY, but declined to play shortly before their scheduled appearance due to the increasing violence at the venue.[8] "That's the way things went at Altamont—so badly that the Grateful Dead, prime organizers and movers of the festival, didn't even get to play," staff at Rolling Stone magazine wrote in a detailed narrative on the event,[9] terming it in an additional follow-up piece "rock and roll's all-time worst day, December 6th, a day when everything went perfectly wrong."[10]

Approximately 300,000 attended the concert,[2][4] and some anticipated that it would be a "Woodstock West".[11] Woodstock was held in Bethel, New York, in mid-August, less than four months earlier.

Jefferson Airplane/Grateful Dead-centered background narrative

According to Jefferson Airplane's Spencer Dryden, the idea for "a kind of Woodstock West" began when he and bandmate Jorma Kaukonen discussed the staging of a free concert with the Grateful Dead and Rolling Stones in Golden Gate Park. Referring to the Stones, Dryden said, "Next to the Beatles they were the biggest rock and roll band in the world, and we wanted them to experience what we were experiencing in San Francisco." As plans were being finalized, Jefferson Airplane were on the road, and by early December they were in Florida, believing the concert plans for Golden Gate Park were proceeding. But by December 4, the plans had broken down, in Paul Kantner's account, because the city and police departments were unhelpful; innate conflict between the hippies of Haight-Ashbury and the police was manifested in obstructiveness. Sears Point Raceway was suggested, but its owners wanted $100,000 in escrow from the Rolling Stones. At the last moment, Dick Carter offered his Altamont Speedway in Alameda County for the festival. Jefferson Airplane flew out of Miami on December 5. Kantner said the location was taken in a spirit of desperation: "There was no way to control it, no supervision or order." According to Grace Slick, "The vibes were bad. Something was very peculiar, not particularly bad, just real peculiar. It was that kind of hazy, abrasive and unsure day. I had expected the loving vibes of Woodstock but that wasn't coming at me. This was a whole different thing."[12]